Question

Which of the pairs of numbers whose sum is 80 has the largest product?

Answer 1

you want just the answer? or the method?

Answer 2

x + y = 80

xy = max

Answer 3

Well both

Answer 4

yea substitute y in the eq. 2 written by moneyboard and maximize

Answer 5

*moneybird sorry for that ^

Answer 6

try doing it here

Answer 7

The two numbers are x and 80-x The product is x(80-x) or 80x -x^2. This is a parabola. The x coordinate of its vertex is -b/2a or -80/-2 or 40. If x is 40 y = 40 and that is the pair of numbers whose sum is 80 that has the greatest product.